1. Field of the Invention
The present invention relates to an input device by which a user inputs coordinate information, etc. while observing a cursor displayed, for example, on a display device.
2. Description of the Prior Art
FIG. 17 is a block diagram showing a simplified form of the configuration of a prior art input device.
The input device of the prior art, indicated by reference numeral 1701 in the figure, comprises a coordinate detection means 1702, a pointing means 1703, a coordinate output terminal 1704, a cursor generating means 1705, an image input terminal 1706, an image generating means 1707, and a display means 1708.
The coordinate detection means, indicated at 1702, detects position information of an object placed in close proximity to the coordinate detection means 1702. The coordinate detection means 1702 outputs the coordinates of the object detected and information indicating whether or not the coordinates of the object are currently detected (hereinafter called the "detection information"). The coordinate detection means 1702 is, for example, an electromagnetic inductance tablet, a resistive film tablet, or an electrostatic capacitance tablet.
The pointing means, indicated at 1703, is the object whose coordinates are to be detected on the coordinate detection means 1702. The pointing means 1703 outputs information indicating whether the coordinate detection means 1702 is being pressed by the pointing means 1703 (hereinafter called the "pressing information").
An example of the structure of the pointing means 1703 will be described in detail below with reference to drawing. FIG. 18 is a diagram showing an example of the structure of the coordinate detection means 1702.
Indicated at 1801 is the pointing means, which comprises a holding means 1802, a pressing detection means 1803, and a coordinate pointing means 1804.
The user operates the pointing means 1801 by holding the holding means 1802 with his hand. The holding means 1802 is shaped, for example, like a penholder.
The pressing detection means, indicated at 1803, detects the pressing of the coordinate detection means 1702 by the pointing means 1801. The pressing detection means 1803 outputs information indicating the detection of the pressing. The pressing detection means 1803 is built into the pointing means 1801, and when a pressing force is applied to the pointing means 1801, the force is also applied to the pressing detection means 1803. The force applied vertically on the coordinate detection means 1702 is thus transmitted to the pressing detection means 1803, accomplishing the detection of the pressing by the pointing means 1801 on the coordinate detection means 1702. The pressing detection means 1803 is, for example, a mechanical push switch.
The coordinate pointing means, indicated at 1804, is located at the tip of the pointing means 1801. The coordinate pointing means 1804 has the property of being able to detect coordinates on the coordinate detection means 1702. For example, when the coordinate detection means 1702 is an electromagnetic induction tablet, the coordinate pointing means 1804 is formed from a ferromagnetic material.
The coordinate output terminal, indicated at 1704, is coupled to the coordinates output from the coordinate detection means 1702 and also to the pressing information output from the pointing means 1703. The coordinate output terminal 1704 is used to connect the input device 1701 to an external device.
The cursor generating means, indicated at 1705, accepts at its inputs the detection information and coordinates output from the coordinate detection means 1702 and the pressing information output from the pointing means 1703, and outputs an image of a cursor.
An example of the image output from the cursor generating means 1705 will be described below with reference to FIG. 19.
Reference numeral 1901 indicates an image output from the cursor generating means 1705, and 1902 designates a cursor. The position of the cursor 1902 in the image 1901 changes in accordance with the input coordinates. Further, the external appearance of the cursor 1902 changes in accordance with the input pressing information and input detection information. For example, when the detection information indicates a coordinates non-detected condition, the cursor 1902 is not displayed. When the pressing information indicates a pressed condition, the cursor 1902 is displayed in a different color than when in an unpressed condition.
The image input terminal, indicated at 1706, is used to input an image from an external device to the input device 1701.
An example of the image input via the image input terminal 1706 will be described below with reference to FIG. 20.
Reference numeral 2001 indicates an image input at the image input terminal 1706, and 2002 designates window images included in the image 2001. The image 2001 input at the image input terminal 1706 is, for example, a display screen produced by an ordinary window system.
The inputs of the image generating means 1707 are coupled to the output of the cursor generating means 1705 and the output of the image input terminal 1706. The image synthesizing means 1707 synthesizes an image, for example, by superimposing an image output from the cursor generating means 1705 over an image input via the image input terminal 1706. The image may be synthesized by taking an intermediate color between the two input images.
An example of the image output from the image synthesizing means 1707 will be described below with reference to FIG. 21.
Reference numeral 2101 indicates an image output from the image generating means 1707. The image 2101 is the image output when the output of the cursor generating means 1705 is the image shown in FIG. 19 and the input of the image input terminal 1706 is the image shown in FIG. 20.
The cursor indicated at 2102 is the same as the cursor 1902 contained in the output of the cursor generating means 1705.
The images indicated at 2103 are the same as the images 2002 contained in the input of the image input terminal 1706.
The display means, indicated at 1708, accepts the image output from the image generating means 1707.
The display means 1708 displays the input image. The display means 1708 is, for example, a CRT display or a liquid-crystal display.
Next, the operation of the prior art input device 1701 will be described with reference to the flowchart shown in FIG. 22.
(Step 2201) When the coordinate detection means 1702 has detected the coordinates of the pointing means 1703, the process proceeds to step 2203.
(Step 2202) The cursor 1902 included in the image generated by the cursor generating means 1705 is changed to a pictorial symbol that indicates non-detection of the coordinates. The generated image is fed to the image synthesizing means 1707 for image synthesis, and the synthesized image is displayed on the display means 1708. Then, the process returns to step 2201.
(Step 2203) The coordinates obtained in step 2202 are output at the coordinate output terminal 1704.
(Step 2204) The cursor generating means 1705 changes the position of the cursor 1902 in accordance with the coordinates output from the coordinate detection means 1702. The generated image is fed to the image generating means 1707 for image synthesis, and the synthesized image is displayed on the display means 1708. Repositioning of the cursor 1902 is thus accomplished.
The amount of movement of the cursor 1902 is determined by the pointer's coordinates obtained by the coordinate detection means 1702. For example, the following method is used. (1) Coordinate values linear with the absolute values obtained by the coordinate detection means 1702 are taken as the absolute coordinates of the cursor 1902. (2) The increase or decrease of the coordinates obtained by the coordinate detection means 1702 are added to or subtracted from the absolute coordinates of the cursor 1902.
(Step 2205) When the coordinate detection means 1702 is in a pressed condition, the process proceeds to step 2208. Otherwise, the process proceeds to step 2206.
(Step 2206) Information indicating an unpressed condition is output at the coordinate output terminal 1704.
(Step 2207) The cursor generating means 1705 generates an image with the cursor 1902 changed to a one indicating an unpressed condition. The generated image is fed to the image generating means 1707 for image synthesis, and the synthesized image is displayed on the display means 1708. The image with the cursor 1902 changed to the one indicating an unpressed condition is thus displayed. The process returns to step 2201.
(Step 2208) Information indicating a pressed condition is output at the coordinate output terminal 1704.
(Step 2209) The cursor generating means 1705 generates an image with the cursor 1902 changed to a one indicating a pressed condition. The generated image is fed to the image synthesizing means 1707 for image synthesis, and the synthesized image is displayed on the display means 1708. The image with the cursor 1902 changed to the one indicating a pressed condition is thus displayed. The process returns to step 2201.
The prior art device described above, however, has required that a special pointing means with built-in pressing detection means be used as the pointing means, and it has not been possible to use a part of a human body, such as a finger, as the pointing means. Therefore, a preparatory action to hold the special pointing means with a hand has been necessary before an operation can be started. As a result, when the operation is performed intermittently with each step lasting for a short duration of time, the time required for the preparatory action has reduced the work efficiency.
Furthermore, since the pressing detection means is built into the pointing means, if the stroke of the pressing detection means is long, the feel when it is pressed by the pointing means is unnatural as compared with ordinary writing tools, resulting in an unpleasant feel. On the other hand, if the stroke is short, an erroneous operation tends to occur since tactile feel enough to distinguish between pressed and unpressed conditions cannot be obtained.
Moreover, for users who have no experience in operating the prior art input device, it has not been possible to understand intuitively that the cursor position changes in accordance with the position of the pointing device on the coordinate detection means.
It is an object of the present invention to overcome the above enumerated deficiencies of the prior art by providing an input device that is natural to operate and reduces user fatigue, and whose method of operation can be acquired intuitively.